Ball-pile tubes



13, 1960 w. H. COBI BALL-FILE TUBES Filed Aug. 12, 1955 United StatesPatent G F BALL-PILE TUBES Walter H. Cobi, Port Chester, NY.

(North St, Greenwich, Conn.)

Filed Aug. 12, 1955, Ser. No. 527,902

4 Claims. (Cl. til-53.6)

This invention relates to concrete piles of the type known ascast-in-place piles and more particularly to piles of this type havingan enlarged concrete foundation or footing and sometimes termed ballpiles or bulb piles.

The invention particularly relates to the formation of the concretefooting at the time and place of installation of such piles.

Piles of this type are frequently used in the support of superstructuresin locations where the solid strata in the ground are covered to greatdepths by watery or muddy layers of varying densities. In such locationsthe lower end of the pile may be terminated in a layer at a depth somedistance above the solid bottom stratum where the increased footing ofthe pile may be properly supported as required by the load, therebyoften greatly reducing the required length of the pile and the demandfor its rigidity.

Such ball piles have been formed by the use of long iron tubes placed tothe required depth in the ground, through which concrete may be pouredand a ram lowered for forcing the concrete out into a ball shape, sothat the surrounding ground may be compacted sufiiciently to carry theassigned load.

Before pouring the concrete, which is to form the ball at the bottom endof the pile, the tube must first be positioned in the ground with itslower end in the stratum where the ball of concrete is ultimately to beformed and positioned. This placing of the tube is usually done byforcing the tube downwardly into the soil, thus forming a hole throughthe ground. In order to keep water and mud out of the tube when the tubeis forced downwardly through the ground, the bottom end of the tube isclosed by some means to make it watertight. Otherwise, water and mudwill creep in and this will contaminate, or dilute, the concrete whichis poured into the tube to be forced out of the lower end to form theball. Such contamination of the concrete would, of course, result in aball of impaired strength. However, when the tube is placed in its finalposition in the ground to receive the concrete and permit it to moveoutwardly from the tube to form an enlarged concrete ball, the lower endof the tube must be open so that the concrete may be forced through it,to form this enlarged concrete foundation ball at the lower end of thepile.

It is a main object of the invention to provide a bottom arrangement forthe pile tube which can withstand the strains incident to the placing ofthe tube in the ground and which prevents external materials such aswater and mud, from entering the tube and which, on the other hand, isremovable in situ when the tube is ultimately placed, so that concretemay be poured into the tube and forced out through its bottom end toform an enlarged concrete foundation ball; that is, a concrete ballhaving a diameter greater than the diameter of the tube.

In accordance with a principal feature of the invention the 'metal wallnear the bottom of the tube used in 2,953,869 Patented Dec. 13, 1960forming the hole in the ground is weakened along a line around theperiphery of the tube.

In accordance with another important feature of the invention theweakening of the tube wall along the line about the periphery of thetube near the bottom thereof is attained by a reduction of material inthe metal wall.

In accordance with one specific feature the said reduction of wallmaterial may be attained by reducing the thickness of the metal wall byforming a groove therein partway or all around the .tube.

In accordance with an alternative feature the said reduction may beattained by a series of apertures through the wall of the tube along thesaid line of weakening.

In accordance with a further specific feature the apertures are suitablyplugged to make them watertight.

Although the novel features which are believed to be characteristic ofthe invention will be pointed out in the annexed claims, the inventionitself as to its objects and advantages and the manner in which it maybe carried out may be better understood by reference to the followingdescription, taken in connection with the accompanying drawings forminga part hereof, in which:

Fig. 1 is a view in elevation illustrating the general arrangement of aball pile, of the type to which the invention appertains, placed inposition in the ground;

Fig. 2 is a view showing in simplified form the bottom portion ofequipment used in placing a ball pile, the line AA indicating the lineof weakening;

Fig. 3 shows the same equipment as Fig. 2 but with the bottom end forcedoff with a charge of concrete;

Fig. 4 shows the bottom end of a tube used in the forming of a hole inthe ground for a ball pile, in which the weakening line is effected by aseries of plugged holes;

Fig. 5 shows parts similar to those in Fig. 4; the tube in this instancebeing corrugated and having a smooth cylindrical bottom portion for theline of weakening;

Fig. 6 shows parts similar to those in Fig. 4; the tube in this instancehaving an attached bottom portion with the line of weakening;

Figs. 7 and 8 show alternative details of the plugging of the holesalong line A-A in the preceding figures;

Fig. 9 shows the bottom part of a corrugated tube and a sleeve bottomplate welded thereto, the line of weakem'ng AA in this case being alonga groove in the cylindrical wall of the bottom plate; and

Fig. 10 shows a detailed cross-section of the weakening feature in Fig.9 taken along line 10-10 of Fig. 9; and

Fig. 11 shows a detailed cross-section of the weakening feature in Fig.9 taken along line 11-11 of Fig. 9.

Referring now to Fig. l the concrete ball pile 10 is shown in positionin the ground and as having a long pile section or shaft 11 and a ballshaped foundation 12. The shaft may extend through different strata moreor less watery, into a stratum firm enough to be compacted into adesired consistency.

The long section 11 extending to the depth AA may be more or less smoothand straight, depending on the manner in which it was installed. Thisconcrete shaft may be in direct contact with the ground for the fulllength or for part of the length. The concrete shaft may however beencased in a permanent steel casing, not shown in Fig. l, which may besmooth or corrugated.

Figs. 2 and 3 show the bottom end of an equipment 20 suitable for theinstallation of a ball pile, such as shown in Fig. l or for forming theshell therefor. It comprises a long steel tube 21, a bottom closure inthe form of a plate or boot 22 and an internal ram 30. Such equipmentmay take different forms and may be used in difierent manners. Butgenerally speaking, the

steel tube 21 with the boot 22 attached is forced downwardly through thesoil by means of ram 30 or by means of driving mandrels known in the artand ultimately is placed at-a depthWhere-the separation line A-A willcorrespond to the depth A-A indicated in Fig. 1, before any concrete ispoured through. The separating line AA-in Figs. 2 and 3 indicate theline of weakening of the tube, the tube and boot remaining intactdurin'gthe installing process. a 7

When the tube is in its final position, the ram 30 is removed and abatch of concrete, of suitable mixture as known in theart, is poureddown through the tube to a level a few feet above line AA. After lockingthe tube to the surface equipment, or otherwise securing the tube inthis position, the ram 30 is lowered and driven by reciprocatingmotionagainst the concrete which now forces the bottom closure or boot off thetube, causing a separation indicated in Fig. 3 by lines AA and BB j bepoured into the tube and tamped more lightly for the formation of thelong shaft 11 up to a level which usually is above ground level, asshown in Fig. l.

The tubing 21 may be left in the ground to the full depth A-A to serveas the shell of the pile 10. However, if it is desired to form aconcrete pile without a permanent steel casing, the tube 21 may beraised a short distance, say a few feet, after the ball has been fullyformed and, after raising the tube this increment, an additional batchof concrete may be poured in and tamped this procedure being repeated,if desired for the full length of the pile, which thus will be left inthe ground without a steel casing.

vIn the latter practice, the tube 21 thus is retrieved and into contactwith the sides of the hole in the ground,

the bottom end closed with a new bottom closure or boot for installationof another similar pile at another location.

In accordance with the invention, the weakened line at AA of the tube 21may be formed in different ways.

In the case of the tube 21, as illustrated in Fig. 2, the

tube has a bottom plate or boot 22 firmly welded to the bottom end ofthe tube so that it is watertight, and the weakening of the tube wall isobtained by means of a series of holes 41 as shown in Fig. 4. The holesmay be drilled or punched through the tube wall along a line the plugs,when inserted in the holes, are protected by 43 around the periphery ofthe tube in a plane through the line A-A and located an inch or so abovethe upturned edge or collar 24 of the boot 22. The distance between theholes will determine the force required to 1 tear the wall part for agiven wall thickness.

In order to keep the bottom end of the tube watertight duringinstallation of the tube in the earth the holes 41 are plugged tight bymeans of plugs or stoppers 45, a sample of which is illustrated in Fig.7. The plug 45 is preferably solid and is tapered slightly for easyinsertion and has a shoulder stop 46 to prevent it from being forced outwhile the wall is still intact. A slight modification is shown in Fig. 8where the plug 450 is indicated as being hollowed out on the side facinginward. The plug is preferably inserted from the inside to prevent itfrom flying out under the heavy tamping on the first charge of concretefor breaking the Wall of the tube along line 43.

The plugs may be made of any suitable material and' should preferably beslightly elasticso that they will -lock-themselves imposition in: theholes 41... They may be of metal, such as soft iron, but preferably aremade of relatively hard rubber.

By locating the line of plugs 45 just above the outside collar 24 of theboot 22, the projecting ends of the plugs will be protected to anappreciable extent against pressure from the sides of the hole in theground while the tube is being forced downward to position.

Fig. 5 shows a weakening line 53 applied to a different type of tube 51.The tube 51 is corrugated for maximum rigidity with aminimum wallthickness. It is terminated by a bottom-closure or boot 52- weldedwatertight to the tube 51. Y I I However when the corrugations in thewall of tube 51 run helically, as shownin Fig. 5, it is somewhatinconvenient to drill or punch the circular holes for the plugs, sincethe plugs should preferably be inserted perpendicular to the Wall areasat the different parts of the corrugations, such as hills, valleys andslopes. For that reason, it is desirable that the corrugations along thebottom edge of the tube 51 be hammered or rolled out into asubstantially smooth cylindrical wall shape 56 for a distance extendingafew inches above the upper edge of boot 52, theboot then being weldedwatertight into position on this cylindrical portion 56.

The weakening line AAis located in the smooth cylinder portion 56 aninch or so above the upper edge of boot 52, and may consist of a seriesof apertures 53 of any'efi'ectiveshaped and closed with plugs made of asuitable materiaLsuch as plugs 45.

For tubes of the corrugated type, such as shown in Fig. 5, anotherarrangement may be provided in accordance with the. invention. One suchother'arrangement is-shown inFig. 6. In this modification the tube 61 iscut off straight at the bottom and is closed by a watertight bottomclosure having a weakened line 63, which is similar to weakened line 53as shown in Fig. 5. This bottom closure comprises a cylindrical wall orsleeve portion 66 and bottom plate 62 is welded thereto. The collarportion of bottom plate 62 is Welded to the bottom edge of thecylindrical wall portion 66. The weakened line 63, is formed in thecylindrical wall portion 66 and the upper edge of the portion 66 iswelded to the bottom edge of the tube 61.

The tube 61, as shown in Fig. 6, is corrugated but, if desired, it maybe a smooth wall tube without corrugations. The sleeve portion 66 of thebottom closure shown in Fig. 6, preferably has corrugations which lie inplanes at right angles to the long axis of the tube 61 and the series ofholes forming the weakened line 63 are placed in the valley of acorrugation, as illustrated in Fig. 8. When the holes are placed in thevalley of a corrugation as shown in Fig. 6, the protruding ends of theadjacent hills of the corrugation, as shown in Fig. 8. This arrangementof bottom closure has advantages in that the entire bottom closureincluding the sleeve 66, having the weakened line 63 may be assembled inthe shop and taken in assembled form to the field, where all that isrequired is the welding of the sleeve 66 to the bottom end of a lengthof standard corrugated tube 61; or, if desired, to a length of smoothwall tube, such as 21, illustrated in Fig. 4.

For tubes made of corrugated sheet steel of 16 or 18 gauge the holes 41may be /2 inch in diameter and /4 inch apart for use with rams ingeneral use in this art. However, the size and spacing of the holes willbe determined by the gauge and strength of the wall of the steel tubeand the force utilized to bring about the separation of the bottomclosure When it is knocked off the end of the tube. V

Fig. 9 shows a method of weakening the bottom end along line AA belowthe line of attachment of the bottom plate or boot, to the tube. Thetube 91 may be any,of. the types, referred to above. The boot 92 has aclosed bottom plate with an upstanding cylindrical collar 96 which fitssnugly around the bottom end of the tube. The collar 96 is weldedwatertight along its upper edge 94 to the wall of the tube 91. Boots ofthis type must be of heavy material, with a wall thickness of inch ormore depending upon the size of the tube, since they force the waythrough the ground for the pile hole. They are of sheet steel and arefrequently stamped in one piece and shaped to fit the tube.

In accordance with a specific feature of the invention the weakeningline A-A is placed in the cylindrical collar portion 96 of the boot,below the line of welding 94. With the heavy wall thickness of thecollar 96 the weakening by means of apertures is not to be recommended.Hence, a narrow groove 93 is cut, as in a lathe, or otherwise formed inthe heavy wall material, deep enough to reduce the thickness at thevalley of the groove to provide the desired weakness. As best shown inFigs. 9 and 11, apertures are provided in groove 93, each aperture beingclosed by a plug or stopper 93a. The plug 93:: may be of the type shownat 45 in Fig. 7 or at 45a in Fig. 8. If desired, the inner side of thewall forming the collar 96, may be turned smooth in the lathe, so thatthe thickness at the inner surface of the valley of the groove may beaccurate and safe. If desired, a groove may be cut in the flat bottompart of the boot 92 at its periphery instead of the collar portion 96 ofthe boot.

The strength at the line of weakening must, of course, be sufiicient topermit easy handling in the field.

When the tube has been placed in final position it becomes necessary toapply disrupting forces by locking the tubing in position in anyconvenient manner and by striking the bottom from inside with a ram,usually through a charge of concrete. The weakening effect thus must becarried to the point where rupture may be secured with availableequipment.

With any of the forms described herein a watertight bottom closure maybe assured so that the consistency of the concrete, prior to the timethe concrete sets, may be relied upon till the time of rupture when theball is to be formed.

The terms and expressions which have been employed herein are used asterms of description and not of limitation, and there is no intention,in the use of such terms and expressions, of excluding any equivalentsof the features shown and described or portions thereof, and it is to berecognized that various modifications are possible within the scope ofthe invention claimed.

What is claimed is:

1. In an equipment for installation of a ball pile in the ground a longsheet steel tube with a closed watertight bottom having a series ofapertures through the wall material to form a line of weakeningcircumferentially about the tube at the bottom end for rupturing saidwall and removal of the bottom by force exerted on the inside of saidtube in a direction toward said bottom, and a separate plug in each ofsaid apertures closing said apertures Water-tight prior to rupture ofsaid wall.

2. A tube in accordance with claim 1 in which said plugs are ofrubberlike material forced ttight into said apertures.

3. A short tubular section of sheet steel having a metal bottom weldedwatertight to one end thereof and closing one end of said tubularsection, a shallow groove disposed circumferentially about said section,a series of holes through the wall of said section closely distributedalong a line in said groove and a plurality of shouldered plugs ofrubberlike material for watertight plugging of all said holes, saidsection being adapted for watertight welding along its open other end toa longer tube for the installation of a ball pile in the ground.

4. A metal bottom closure for watertight attachment to a long sheetmetal tube for the installation of a concrete ball pile in the ground,said closure comprising a circular bottom plate and a cylindrical wallportion upstanding therefrom for welding said closure watertight to saidtube, a groove extending circumferentially around said cylindrical wallportion, a plurality of apertures disposed in said groove, said grooveand said apertures forming a line of weakening in said cylindrical wallportion around its periphery in a plane parallel with said bottom platefor separation of said bottom plate from said cylindrical wall along theweakened line by rupturing the metal in said plane by the application offorce exerted inside said cylindrical Wall against said bottom plate anda filling material closing said apertures watertight.

References Cited in the file of this patent UNITED STATES PATENTS1,794,892 Goldsborough Mar. 3, 1931 1,900,622 Tada Mar. 7, 19331,951,645 Boosey Mar. 20, 1934 2,277,758 Hawkins Mar. 31, 1942 2,326,872Marsden Aug. 17, 1943 2,631,435 Ernshwiller Mar. 17, 1953 2,791,900Ruben May 14, 1957 FOREIGN PATENTS 292,903 Germany July 4, 1916 423,694Germany Jan. 9, 1926 43,985 Netherlands Sept. 15, 1938 1,010,103 FranceMar. 19, 1952 518,438 Belgium Mar. 31, 1952 693,465 Great Britain July1, 1953

